18.5.10.19 The ndbinfo transporters Table

This table contains information about NDB transporters.

The following table provides information about the columns in
the transporters table. For each column, the
table shows the name, data type, and a brief description.
Additional information can be found in the notes following the
table.

Column Name

Type

Description

node_id

integer

This data node's unique node ID in the cluster.

remote_node_id

integer

The remote data node's node ID.

status

string

Status of the connection.

remote_address

string

Name or IP address of the remote host

bytes_sent

integer

Number of bytes sent using this connection

bytes_received

Number of bytes received using this connection

connect_count

Number of times connection established on this transporter

overloaded

1 if this transporter is currently overloaded, otherwise 0

overload_count

Number of times this transporter has entered overload state since
connecting

slowdown

1 if this transporter is in scan slowdown state, otherwise 0

slowdown_count

Number of times this transporter has entered scan slowdown state since
connecting

For each running data node in the cluster, the
transporters table displays a row showing the
status of each of that node's connections with all nodes in
the cluster, including itself. This
information is shown in the table's
status column, which can have any one of
the following values: CONNECTING,
CONNECTED, DISCONNECTING,
or DISCONNECTED.

Connections to API and management nodes which are configured but
not currently connected to the cluster are shown with status
DISCONNECTED. Rows where the
node_id is that of a data nodes which is not
currently connected are not shown in this table. (This is
similar omission of disconnected nodes in the
ndbinfo.nodes table.

The remote_address,
bytes_sent, and
bytes_received columns were added in MySQL
Cluster NDB 7.2.9. The remote_address is the
host name or address for the node whose ID is shown in the
remote_node_id column. The
bytes_sent from this node and
bytes_received by this node are the numbers,
respectively, of bytes sent and received by the node using this
connection since it was established; for nodes whose status is
CONNECTING or
DISCONNECTED, these columns always display
0.

The connect_count,
overloaded, overload_count
,slowdown, and
slowdown_count columns were added in MySQL
Cluster NDB 7.2.10. These counters are reset on connection, and
retain their values after the remote node disconnects. Also
beginning with MySQL Cluster NDB 7.2.10, the
bytes_send and
bytes_received counters are reset on
connection as well, and so retain their values following
disconnection. (Previously, the values in these columns were
reset on disconnection.) (Bug #15935206)

Assume you have a 5-node cluster consisting of 2 data nodes, 2
SQL nodes, and 1 management node, as shown in the output of the
SHOW command in the
ndb_mgm client:

If you shut down one of the data nodes in this cluster using the
command 2 STOP in the
ndb_mgm client, then repeat the previous
query (again using the mysql client), this
table now shows only 5 rows—1 row for each connection from
the remaining management node to another node, including both
itself and the data node that is currently offline—and
displays CONNECTING for the status of each
remaining connection to the data node that is currently offline,
as shown here: